Computational structural analysis and testing of Bi-Steel plate
Bi-Steel panels are a new composite construction system developed by Corus formerly British Steel Plc. The comprise of steel plates permanently coupled by a matrix of transverse friction welded rods with a concrete in-fill. Numerical modelling using finite element analysis has been conducted on Bi-Steel plates with and without in-filled concrete. The results of non-linear analysis are compared with new and existing experimental data. Both material and geometrical non-linearity were considered in the computer analysis. The shear strength and deformation capacity of the Bi-Steel unit subject to push-out load is discussed. The steel and concrete interface is considered extensively in a series of contact studies. A range of element types is used to examine the effect of modelling the interface as a smeared or discrete contact. Mathematical modelling is used in conjunction with experimental data to validate solution accuracy. The inclusion of a smeared cracking and crushing mechanism has allowed the accurate modelling of concrete. A new method of differential smeared element reinforcement is proposed to maximise accuracy and numerical stability. The failure of a panel subject to an applied bending force is analysed to determine the combined effect of flexure and shear. Finally, a design model has been suggested to calculate the shear strength and deformation capacity of any section size. This research has indicated that Bi-Steel bars and plates have significant shear strength. The shear strength is affected by several important parameters. These include plate spacing, bar spacing and bar diameter. From load-deformation relationships it can be seen that Bi-Steel plates have high ductility and deformation capacity. For very thick plates (>12mm), the failure can be brittle if bar numbers are small. The failure will be initiated by shear failure at the weld interface.